Word: giacobinid
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...sized meteorites reach the earth intact, while the smaller ones "burn" to vapor on passing through the atmosphere. But Dr. H. E. Landsberg at the U.S. Weather Bureau had another idea. He smeared some microscope slides with glycerin and exposed them on a mountaintop just before a shower of "Giacobinid" meteors* was expected. Before and during the shower, he caught nothing unusual. But for many days after the shower he caught highly magnetic particles unlike anything found in normal dust-catches...
...speed of Giacobinid meteors is rather accurately known: 23 kilometers (14.3 miles) per second. Working theoretically, Whipple figured out what would happen to a very small particle hitting the thin top of the atmosphere at this speed. He decided that if the particle were small enough, about 4 microns (.000156 in.) in diameter, the heat generated by its friction with the air would be carried away (by radiation and other effects) without heating the particle. The "critical size" that he calculated theoretically was close to the actual size of Landsberg's particles. This is strong evidence, said Whipple, that...
| 1 |